High solids material moving apparatus

ABSTRACT

Described herein is a material moving apparatus having a chamber that includes a chamber having a cross-sectional shape and a discharge opening; a pumping ram mounted in the chamber configured to move material out of the discharge opening of the chamber; and a discharge pipe connected to the discharge opening of the pump and having and an inlet and an outlet and a cross-sectional shape corresponding to the cross-sectional shape of the discharge opening.

This application claims the benefit of U.S. Provisional Application No. 61/174,248, filed Apr. 30, 2009, the content of which is herein incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Material moving pumps are known for moving liquids, solids or liquid entrained discrete solid material, or other product, for example manure, straw, crushed animal bones, sawdust, or feathers. Typically material moving pumps include a ram that reciprocates in a chamber undergoing a working stroke or power stroke during which material is moved through the chamber, and a return stroke whereby the ram returns to its starting position and more material is introduced into the chamber ahead of it. Such pumps are satisfactory for the pumping many materials.

SUMMARY OF THE INVENTION

Described herein is a material moving apparatus that includes a chamber having a cross-sectional shape and a discharge opening; a ram mounted in the chamber configured to move material out of the discharge opening of the chamber; and a discharge pipe having an inlet and an outlet, wherein the discharge pipe is connected to the discharge opening and has a cross-sectional shape that corresponds to the discharge opening cross-sectional shape. In one embodiment, the discharge pipe outlet has a size that is substantially similar to the discharge pipe inlet. In another embodiment, the discharge pipe outlet has a size that is greater than the size of the discharge pipe inlet. In one embodiment, the discharge pipe has a substantially constant size such that the discharge pipe outlet has a size that is substantially the same as the discharge pipe inlet. In another embodiment, the discharge pipe is tapered such that the discharge pipe outlet has a size that is greater than the discharge pipe inlet. In another embodiment, the discharge pipe has more than one section. In one embodiment, the discharge pipe sections have a stepped configuration. In another embodiment, the discharge pipe sections have alternating/interspersed tapered and constant sections. In one embodiment, the chamber has a downwardly converging cross-sectional shape and the discharge pipe has a corresponding downwardly converging cross-sectional shape. In one embodiment, the downwardly converging sidewalls of the chamber converge at a point and the chamber has a triangular cross-sectional shape and the discharge pipe has a corresponding triangular cross-sectional shape.

This summary is an overview of some of the teachings of the present application and is not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details are found in the detailed description and appended claims. Other aspects will be apparent to persons skilled in the art upon reading and understanding the following detailed description and viewing the drawings that form a part thereof, each of which is not to be taken in a limiting sense. The scope of the present invention is defined by the appended claims and their legal equivalents.

IN THE DRAWINGS

FIG. 1 is a schematic top plan view of a material moving apparatus described herein;

FIG. 2 is a schematic side elevational view of the material moving apparatus of FIG. 1;

FIG. 3 is a schematic cross sectional view of the material moving apparatus of FIG. 2 taken along line 3-3;

FIG. 4 is a schematic top plan view of a material moving apparatus with a discharge pipe described herein;

FIG. 5 is a schematic side elevational view of the material moving apparatus of FIG. 4;

FIG. 6 is a schematic cross-sectional view of the material moving apparatus of FIG. 4 taken along line 6-6;

FIG. 7 is a schematic top plan view of a material moving apparatus with a discharge pipe described herein;

FIG. 8 is a schematic side elevational view of the material moving apparatus of FIG. 7;

FIG. 9 is a schematic top plan view of a material moving apparatus with a discharge pipe described herein;

FIG. 10 is a schematic side elevational view of the material moving apparatus of FIG. 9;

FIG. 11 is a cross-sectional illustration showing the dimensions of the discharge pipe in FIG. 9 taken along line 11-11;

FIG. 12 is a cross-sectional illustration showing the dimensions of the discharge pipe in FIG. 9 taken along line 12-12;

FIG. 13 is a cross-sectional illustration showing the dimensions of the discharge pipe in FIG. 9 taken along line 13-13;

FIG. 14 is a cross-sectional illustration showing the dimensions of the discharge pipe in FIG. 9 taken along line 14-14;

FIG. 15 is an illustration of the pressure in a triangular discharge pipe;

FIG. 16 is an illustration of the pressure in a circular discharge pipe;

FIG. 17 is an illustration of an altitude of a right triangle;

FIG. 18 is a schematic top plan view of a material moving apparatus with a discharge pipe described herein;

FIG. 19 is a schematic side elevational view of the material moving apparatus of FIG. 18; and

FIG. 20 is a cross-sectional illustration of a discharge pipe with ribs.

While the invention is susceptible to various modifications and alternative forms, specifics thereof have been shown by way of example and drawings, and will be described in detail. It should be understood, however, that the invention is not limited to the particular embodiments described. On the contrary, the intention is to second modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

DETAILED DESCRIPTION

Although industrial pumping equipment is known and is widely used, conventionally available pumps typically cannot pump a material having more than 10% solids by weight. Described herein is a system and apparatus for pumping high solids materials. As used herein, the term “high-solids material” includes dry and low moisture materials including materials having more than about 10%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, 75%, 80% or 90% solids by weight.

In one embodiment, the material is compressible. As used herein, the term “compressible” refers to the tendency of a material to change its volume and density when subjected to pressure, for example, the volume of a compressible material can be reduced in response to applied pressure. In some materials, the compressible material retains its compressed shape, even after the pressure is removed or decreased. In some embodiments, the compressible material slowly expands after the pressure is removed or decreased.

Examples of solid materials include bio-solids, which include, but are not limited to, saw dust, yard trimmings, compost, wood chips, straw, grass, corn cobs, and corn stover. Other materials include garbage or waste material, including, but not limited to, bottles, cans, clothing, disposables, food packaging, and food scraps. Still other materials include paper materials, including, but not limited to, newspapers, magazines, cardboard, office paper, and paper bags. Other solid material can include plastics, including, but not limited to plastic bags, milk jugs and other storage containers. The high-solids material can also include mixtures and combinations of the materials listed herein or other similar materials.

Conventional “pumpable” materials are generally liquids that have no fixed shape, but rather an ability to take on the shape of the container in which they are placed. The response of a typical “pumpable” liquid to an applied pressure or pressure gradient is to flow. Therefore, the “pumpable” liquid will tend to flow out of a pumping chamber and into a discharge pipe when subjected to pressure.

In contrast, when pressure or a shear stress is applied to a high-solids material, conventionally considered “unpumpable,” the volume and density of the material may change, but the material may not flow or, depending upon the solids content, may flow very little. In one embodiment, the high solids material is elastic, such that the material deforms under pressure but returns to its original shape when the stress is removed. In another embodiment, the high solids material is plastic, such that the material deforms under pressure, but does not return to its original shape when the stress is removed.

When some materials having more than 10% solids by weight are pumped using conventional pumping equipment, the material compresses due to friction between the material and the interior surface of the equipment. As more material is pumped from a pumping chamber into a discharge pipe, the material is further compacted and compressed and the frictional forces are further increased. To date the only method to pump high solids material is to increase the pumping pressure to overcome the frictional forces between the material and the surfaces of the equipment. However, even with increased pressure, the pumping distance is very limited due to the high frictional forces. The discharge pipe becomes plugged with material, which needs to be cleaned out or replaced. This results in a costly and time consuming process, resulting in many high-solids materials being considered un-pumpable.

Many commercial pumps have a pumping chamber with downwardly converging sidewalls, often a triangular shaped chamber. Thus, for the sake of simplicity, the disclosure herein emphasizes a pump with a triangular shaped chamber. However, other suitable shaped chambers are possible and one of skill in the art could readily apply the teachings herein thereto. For many high-solids materials, the pressure exerted by the ram when the material is moved through the chamber causes the material to take on the shape of the chamber. Once the pressure is removed from the block of compressed material, for example, when the block is removed from the chamber, the pressure within the block is relieved by the expansion of the block. For some materials, the block of compressed material tends to stay in the shape of the chamber even after expanding. For example, a compressed material may stay in the shape of a triangular block, even after removal from a triangular shaped pumping chamber. When non-circular blocks of material are pumped into a conventional pipe having a circular cross-section, the blocks of material can rotate and flip, resulting in a stack or jumble of blocks in the circular pipe. As more blocks are added to the pipe, the pipe becomes plugged or blocked.

Described herein is a pump in which high solids materials, previously considered to be unpumpable, can be pumped efficiently, over substantial distances, at relatively low pressure. In general, the pump described herein has a discharge pipe with a cross-sectional shape that corresponds to the cross-sectional shape of the chamber. The correspondingly shaped discharge pipe can be the same or a larger size than the chamber. In some instances, a larger size discharge pipe may be desirable, since it allows for slow and controlled expansion of the block of material. In general, the discharge pipe should be large enough to allow for expansion of the material, but not so large that the blocks of material are able to rotate or flip within the discharge pipe. In essence, the discharge pipe operates as a constraining device, limiting the expansion and rotational movement of the compressed blocks of material. The appropriate size differential between the chamber and the discharge pipe can vary depending upon the physical properties of the high solids material. In one embodiment, the discharge pipe is at least about 1% larger than the chamber, at least about 5% larger than the chamber, at least about 10% larger than the chamber, or at least about 25% larger than the chamber, or up to about 50% larger than the chamber. In another embodiment, the discharge pipe is tapered to allow the material to expand slowly without rotating or stacking within the discharge pipe.

By using a discharge pipe having a shape that corresponds to the shape of the pumping chamber and/or discharge opening of the pumping chamber, high solids materials can be pumped a much farther distance than previously possible. While not wishing to be bound by theory, it is believed that high solids materials are pumpable when the natural tendencies of the material to compress and remain in a compressed shape are considered and a mechanism is provided to allow for a slow decompression and controlled expansion of the compressed material.

Material Moving Apparatus

FIGS. 1-5 show a material moving apparatus indicated generally at 10. Although the disclosure herein focuses on the use of a pump, the invention described herein is applicable to many different types of material moving equipment in which compressed high solid material is transferred from one location to another. For example, in one embodiment, the material moving apparatus can be a compactor, such as trash compactor, to which a discharge pipe is connected.

In general, a material moving apparatus 10 includes a chamber 32 into which high solids material is introduced. The high solids material is then transferred from the chamber 32 into a discharge pipe 60. In one embodiment, the chamber 32 is a pumping chamber in which a plunger or ram 50 assembly is mounted for reciprocation along a longitudinal axis X-X. The chamber 32 can be any suitable size. The cross-sectional shape of the chamber 32 (i.e., perpendicular to the longitudinal axis X-X) can be any suitable shape, including circular, square, triangular, trapezoidal, rectangular, oval, and the like. In one embodiment, the cross-sectional shape of the chamber 32 is non-circular (i.e., is not a circle). In another embodiment, the chamber 32 has parallel side-walls, for example, a square or rectangular cross-sectional shape. In yet another embodiment, the chamber 32 has non-parallel side walls. In yet another embodiment, the chamber 32 has downwardly converging non-parallel side walls, where the sidewalls meet at a bottom surface or a point of the chamber 32. In the embodiment shown in FIG. 3, the non-parallel sidewalls 37, 38 are substantially planar and oriented in an upwardly open V-configuration that terminates in an apex at the base 36 of the apparatus 10. However, other converging configurations are known and can be used, including, for example, a downwardly converging chamber having curved sidewalls or a curved base is possible, for example, a chamber having a parabolic or inverted bell cross-sectional shape, or a pump having substantially planar non-parallel tapering sidewalls that terminate at a substantially planar base, thereby approximating a trapezoid in cross-section. In one embodiment (not shown), the sidewalls and base angles of the trapezoid are substantially the same and form an isosceles trapezoid. If desired, the material moving apparatus 10 can be mounted on support legs 11.

In one embodiment, the side walls 37, 38 define a chamber 32 that has a proximal end 44 defined by a rear wall 31 of the chamber 32 and a distal end 35 defined by a discharge opening 40 of the apparatus 10. The sidewalls 37, 38 define an inlet opening 33 at the top of the chamber 32. In one embodiment, the inlet opening is located at the widest horizontal dimension of the chamber 32 to facilitate receipt of high solids material from the collection hopper 20. In general, it is desirable to have a large inlet opening 33 for the chamber 32 to provide a wide feed point for the solids material. Downwardly converging sidewalls 37, 38 help funnel the solids material to the base 36 of the chamber 32. In the embodiment shown in FIG. 2, the inlet opening 33 of the chamber 32 is located at the proximal end 44 of the chamber 32. If desired, a top or cover 39 can enclose the distal end 34 of the chamber 32. The cover 39 can be removable for purposes of accessing the chamber 32 for cleaning or other maintenance.

The invention described herein can be used in connection with any sized material moving apparatus, from small scale pumps having a pumping chamber size of no more than about 3 inches, no more than about 6 inches or no more than about 9 inches, to industrial sized pumps having sizes greater than about 11 inches, greater than about 16 inches, greater than about 20 inches, greater than about 24 inches, greater than about 30 inches or even greater than about 36 inches. In one embodiment, shown in FIG. 3, the cross sectional shape of the chamber 32 is a right triangle, wherein the right angle is located at the base 36 of the chamber 32. When referring to the “size” of a right triangle herein, the length of the hypotenuse is being discussed. Thus, when used in connection with the chamber 32, the term “size” refers to the length of the chamber cover 39 (e.g., the distance between the tops of the two sidewalls 37, 38). For chambers having other cross-sectional shapes, the term “size” can refer to the greatest distance between the sidewalls of the chamber, for example, the “size” of a semi-circular (or half circle) chamber would be the diameter of the circle.

Use of a discharge pipe 60 having a shape that corresponds to the shape of the chamber 32 results in a significant reduction in frictional forces between the high solids material and the interior surfaces of the discharge pipe 60. The reduced friction allows the material to be pumped at a relatively low pressure, as compared to conventional pumping equipment in which a discharge pipe having a circular cross-section is used. In general, the pumping pressure can vary depending upon the physical properties of the high solids material, the size of the pump and the pumping distance. Additionally, the pumping pressure can be affected based on whether the material is pumped into a pressurized container, into a container at atmospheric pressure, or into a vacuum. However, in some embodiments described herein, the pumping pressure can be reduced to less than about ½ of the pressure used in conventional pipes, to less than about ⅓ of the pressure used in conventional pipes, or to less than about ¼ of the pressure used in conventional pipes. In fact, the reduction in pressure is possible while pumping the material a greater distance as compared to conventional discharge pipes.

The apparatus 10 can also include a hopper 20 for introduction of material into the chamber 32. The hopper 20 includes a hopper opening 21 defined by one or more hopper 20 sidewalls 22, 23, 24, 25 and is configured for contiguous relationship to and to be coextensive with the inlet opening 33 of the chamber 32 such that the high solids material is transferable from the inside of hopper 20 to the chamber 32.

In the embodiment shown in FIG. 2, the hopper 20 is configured to abut the inlet opening 33 of the chamber 32 at the proximal end 44 thereof. In the embodiment shown in FIG. 2, the rear wall 22 of the hopper 20 is substantially in vertical alignment with the rear wall 31 of the chamber 32.

The hopper 14 can be divided into two stages with an upper collection portion 26 and a lower passageway 27. In one embodiment, the upper collection portion 26 can include downwardly converging side walls extending from hopper opening 21 to the lower passageway 27. The lower passageway 27 can include side walls connected to and integrally extended from the lower edges of the respective sidewalls of the collection portion 26. In one embodiment, the sidewalls of the lower passageway 27 form a vertically extended passageway in which the horizontal dimensions of the passageway remain relatively constant through the vertical length thereof.

The apparatus 10 also includes a plunger or ram 50 assembly mounted for reciprocation in chamber 32. In general, the ram 50 is configured to substantially conform to the interior shape and dimensions of the chamber 32, allowing suitable clearance. In the embodiment shown in FIG. 1, the ram 50 is generally V-shaped, with downwardly converging side walls 52, 53 terminating in an apex 54. The ram 50 can include a forwardly directed face 51 to help efficiently move material through the chamber 32. In the embodiment shown in FIG. 1, the face 51 of the ram 50 is generally triangular in shape to confirm to the triangular shape of the chamber 32. The ram side walls 52, 53 are generally disposed in adjacent, close parallel relationship to the side walls 37, 38 of chamber 32. The ram top surface generally follows or is parallel to the inner surface of the cover 39 when working in the distal end 35 of chamber 32. In one embodiment, the ram side walls 52, 53 are in contact with the interior surface of the chamber.

Any suitable motor for reciprocation of ram 50 in chamber 32 can be used, including, mechanical, hydraulic, pneumatic, electrostatic and electrical motors. In one embodiment, the motor includes a double-acting hydraulic reciprocating motor that includes an elongate, hydraulic cylinder 55.

In use, high solids material is placed into the chamber 32. The ram 50 advances in the chamber 32 (working stroke or power stroke) to push the high solids material towards the discharge opening 40. When the ram 50 reaches a first location within the chamber 32, the movement of the ram 50 is reversed in toward the rear of the chamber 32 (reverse stroke). When the ram 50 reaches a second location, direction is again reversed to advance the ram 50 in the chamber 32 for reciprocal movement to the first location. If desired, the apparatus 10 can also include one or more pressure sensors capable of sensing a jam or blockage in the discharge pipe 60 or the presence of a bulky non-compressible material that may not be suitable for pumping.

Discharge Pipe

At the distal end 35 of the chamber 32, the sidewalls 37, 38 and cover 39 define a discharge opening 40. The discharge opening 40 includes a flange 41 or other device configured for connecting a proximal end 70 of a discharge pipe 60 to the apparatus 10. Correspondingly, the discharge pipe 60 includes a mating device or flange (not shown) configured for attachment to the discharge opening 40 of the apparatus 10.

According to one embodiment, the discharge pipe 60 has a cross-sectional shape having a geometry that corresponds to the cross-sectional shape of the discharge opening 40. As used herein, the term “shape” refers to the two-dimensional outline of an object. As used herein, the term “corresponding” refers to two shapes that have a comparable number, orientation and proportion of straight line elements, curved line elements and angles. For example, for a triangular shape a corresponding geometry is a triangle. For a trapezoidal shape, a corresponding geometry is a trapezoid. For a square, a corresponding geometry is a square. For a circular shape, a corresponding geometry is a circle. Although in the examples provided, the corresponding shape has an identical number of straight line elements, curved line elements and angles, some deviation in the number and type of elements is possible while still accomplishing the desired function of the discharge pipe (e.g., controlling or constraining rotational movement and/or expansion of the compressed material). For example, a discharge pipe having a non-equilateral pentagonal shape, with a substantially triangular “base” portion and a somewhat rectangular “expansion area” can correspond to a discharge opening 40 having a triangular shape. Alternately, a V-shaped discharge pipe (i.e., without a cover), can correspond to a triangular shaped discharge opening 40. Additionally, the relative lengths of the sides and the size of the angles need not be identical (i.e., some deviation is acceptable).

In another embodiment, the discharge pipe 60 has as cross-sectional shape that is similar to the cross-sectional shape of the discharge opening 40. As used herein, two shapes are said to be “similar” if each internal angle is equal to an internal angle of the other and all sides of one shape are in equal number and proportion to sides of the other shape. Notably, two shapes can be similar in shape, but not in size. If the discharge pipe 60 has substantially the same size and shape as the discharge opening 50, the two shapes are said to be “congruent.”

In the embodiment shown in FIG. 3, a discharge opening 40 from chamber 32 is triangular in cross sectional shape and is surrounded by a flange 41 for connection to a discharge pipe 60. In the embodiment shown in FIG. 6, the discharge pipe 60 has a corresponding triangular cross-sectional shape, e.g., an apex 66 located at the base of the discharge pipe 60, two legs or sidewalls 67, 68 extending from the apex 66 and a cover 69 opposite the apex 66. In an alternate embodiment, the discharge pipe 60 does not have a cover.

The term “triangle” refers to a polygon with three corners and three sides. Many types of triangles exist and are suitable for use in connection with the chamber 32 or discharge pipe 60 described herein. In an equilateral triangle, all sides are the same length and all angles are equal (60°). In an isosceles triangle, at least two sides are equal in length with two equal angles: the angles opposite the two equal sides. In a scalene triangle, all sides and internal angles are different from one another. A right triangle has one of its internal angles equal to 90° (a right angle). The side opposite to the right angle is the hypotenuse. The other two sides are the legs of the triangle. Any of these types of triangles can be used for the chamber 32 and/or discharge pipe 60.

In one embodiment, the apex or base 36 of the pump forms a right angle and the cross-sectional shape of the chamber 32 is an isosceles triangle, in which the two sidewalls 37, 38 form the legs of the triangle and are equal in length. In this embodiment, the chamber cover 39 forms the hypotenuse of the right triangle. A discharge pipe with a corresponding cross-sectional shape may then have an apex 66 and sidewalls 67, 68 that form a triangle. In one embodiment, the cross-sectional shapes of the two triangles are similar (i.e, the discharge pipe 60 forms an isosceles right triangle). In another embodiment, the shapes of the two triangles are congruent (i.e., the same size). In another embodiment, the cross-sectional shape of the discharge pipe 60 corresponds to, but is larger than the cross-sectional shape of the chamber 33. In one embodiment, the discharge pipe is at least about 1% greater in size than the discharge opening 40, or at least about 2% greater in size than the discharge opening 40, at least about 5% greater in size than the discharge opening 40, but generally less than about 50% greater in size than the discharge opening 40, or less than about 25% greater in size than the discharge opening 40, or less than about 10% greater in size than the discharge opening 40.

In the embodiment shown in FIGS. 7-10, the angle of the apex or base 66 of the discharge pipe 60 is approximately a right angle (90°) and the cross-sectional shape of the discharge pipe 60 is an isosceles triangle, in which the two sidewalls 67, 68 form the legs of the triangle and are equal in length. The cover 69 of the discharge pipe 60 forms the hypotenuse of the right triangle. However, it is not necessary that the cross-sectional shape of the chamber 32 and/or the discharge pipe 60 be a right triangle. The cross sectional shape can be an oblique triangle (i.e., a triangles that does not have a 90° internal angle), an acute triangle (i.e., a triangle in which all the internal angles smaller than 90°), or an obtuse triangle (i.e., a triangle that has one angle larger than 90°).

In one embodiment, shown in FIGS. 4 and 5, the cross sectional shape of the discharge pipe 60 has a substantially constant size moving from the proximal end 70 of the discharge pipe 60 towards the distal end 75 of the discharge pipe. When referring to the “size” of a right triangle, the length of the hypotenuse is being discussed. The term “size” of the discharge pipe 60 thus refers to the hypotenuse of a right triangle, or the length of discharge pipe cover 69 (e.g., the distance between the two sidewalls 67, 68). As used herein, the term “substantially constant” means that the size is the same within an accepted margin of error. In this embodiment, referred to herein as a “constant” discharge pipe, the length of the two sidewalls 67, 68 and the cover 69 remain substantially constant along the length of the discharge pipe 60. The constant discharge pipe 60 can be visualized as shown in FIGS. 4 and 5, in which the length of C (the hypotenuse at the outlet 62 of the discharge pipe) is substantially the same as the length of B (the hypotenuse at the inlet 61 of the discharge pipe) and the length of F (the altitude at the outlet 62 of the discharge pipe 60) is substantially the same as the length of E (the altitude at the inlet 61 of the discharge pipe 60).

When referring to the “size” of a triangle that is not a right triangle, any suitable linear referent can be used, for example, the altitude A of the triangle can be used. The “altitude” refers to a straight line extending through the apex 36 of the triangle (located at the base 36 of the chamber 32) and perpendicular to (i.e. forming a right angle with) the chamber cover 39 (see, FIG. 17). The term “altitude,” when used in connection with a discharge pipe 60 that is not a right triangle refers to a straight line extending through the apex 66 of the discharge pipe 60 and perpendicular to the cover 69 of the discharge pipe 60. As used herein, the term “substantially constant” means that the size is the same within an accepted margin of error. In this embodiment, the length of the two sidewalls 67, 68 and the cover 69 remain substantially constant along the length of the discharge pipe 60, as does the altitude of the triangle. For non-triangular shapes, the “size” can refer any other linear measurement of the shape, such as the length of a side or a diameter of the shape.

In another embodiment, shown in FIGS. 7 and 8, the discharge pipe 60 is tapered such that the size of the cross-sectional shape increases from the proximal end 70 of the discharge pipe 60 moving towards the distal end 75 of the discharge pipe. Put another way, an inlet 61 of the discharge pipe 60 may have a smaller size than an outlet 62 of the pipe. A tapered discharge pipe 60 is believed to allow the blocks of compressed material to relax and gradually expand as the material moves from the proximal end 70 to the distal end 75 of the discharge pipe 60. In one embodiment, the taper results in a proportional or uniform scaling of the cross-sectional shape of the discharge pipe 60 wherein corresponding angles of the two shapes are equal and the corresponding sides are in proportion. However, in other embodiments, the taper need not result in a proportional or uniform increase in size. The taper can be visualized as shown in FIGS. 7 and 8, in which the length of B (the hypotenuse at the outlet 62 of the discharge pipe) is greater than the length of A (the hypotenuse at the inlet 61 of the discharge pipe) and the length of E (the altitude at the outlet 62 of the discharge pipe 60) is greater than the length of D (the altitude at the inlet 61 of the discharge pipe 60).

As shown in FIG. 15, the compressed block of high solids material 12 tends to rest along the base of the discharge pipe 60. As the size of the discharge pipe increases, an “expansion area” 65 is provided near the cover 69 of the discharge pipe 60. While not wishing to be bound by theory, it is believed that providing an expansion area 65 in to which the compressed block of material 12 is able to expand, allows the pressure within the block of material to be relieved, along with the pressure exerted on the sidewalls 67, 68. Hence, the friction between the solid material and the interior surfaces 63, 64 of the sidewalls 67, 68 is reduced. In contrast, in a circular discharge pipe (shown in FIG. 16), the compressed material 12′ exerts a pressure P in all directions, resulting in increased friction along the length of the discharge pipe 60.

In general, to reduce costs and the size of the discharge pipe 60, it may be desirable to have a discharge pipe 60 with the least amount of taper necessary to maintain the friction forces between the compressed material 100 and the sidewalls 67, 68 of the discharge pipe 60 less than the force exerted by the apparatus 10. In one embodiment, the taper results in an increase in size of at least about 1% per linear foot of pipe, or at least about 2% per linear foot, or at least about 3.5% per linear foot and up to about 10% per linear foot, or up to about 5% per linear foot, or up to about 4% per linear foot. In one embodiment, the taper results in an increase in size of between about 2% and about 3.5% per linear foot.

For example, for a 3 inch pump (i.e., a right triangle chamber 32 with a cover 39 having a length of 3 inches between the two sidewalls 37, 38), it may be desirable to have a 3 inch discharge pipe 60 (i.e., a right triangle discharge pipe 60 with a cover 69 having length of 3 inches between the two sidewalls 67, 68) at the inlet 61 of the discharge pipe 60 that tapers over a distance of 5 linear feet to a size of 3.5 inches at the outlet 62 of the discharge pipe. As the size of the apparatus 10 increases, a proportional increase in the taper may be desirable. For example, for a 6 inch pump, it may be desirable to have a 6 inch discharge pipe 60 at the inlet 61 of the discharge pipe 60 that tapers over a distance of 5 linear feet to a size of 7 inches at the outlet 62 of the discharge pipe. In another example, for a 30 inch pump, it may be desirable to have a 30 inch discharge pipe 60 at the inlet 61 of the discharge pipe 60 that tapers over a distance of 5 linear feet to a size of 35 inches at the outlet 62 of the discharge pipe.

In another embodiment, shown in FIGS. 18 and 19, the discharge pipe 60 includes more than one sections that are “stepped” from the proximal end 70 to the distal end 75 of the discharge pipe, in which the size of the inlet 61 of a distal pipe section is greater than the size of the outlet 62 of an adjacent proximal pipe section. As used herein, the terms “distal pipe section” and “proximal pipe section” are relative to one another such that a specific section of pipe can be distal to a first section of pipe, but proximal to a second section of pipe. The term “distal pipe section” refers to a section of discharge pipe that is located closer to the distal end of the discharge pipe than another pipe section. The term “proximal pipe section” refers to a section of discharge pipe that is located closer to the proximal end of the discharge pipe than another pipe section. The desired increase in size from a proximal discharge pipe 60 to an adjacent distal discharge pipe 60 can vary depending upon the physical properties of the solids material being pumped. In general, to reduce costs and the size of the discharge pipe 60, it may be desirable to have a discharge pipe 60 with the least increase in size necessary to maintain the friction forces between the compressed material 100 and the sidewalls 67, 68 of the discharge pipe 60 less than the force exerted by the apparatus 10. In one embodiment, the step results in an distal pipe section having a size that is at least about 1%, or at least about 2%, or at least about 3.5% and up to about 10%, or up to about 20%, or up to about 30%, 40% or 50% greater than an adjacent proximal pipe section. For example, a discharge pipe 60 can be 3 inches at the outlet 62 of a proximal pipe section and 4 inches at the inlet 61 of the adjacent distal pipe section.

In yet another embodiment, shown in FIGS. 9 and 10, the discharge pipe 60 includes alternating or intermittent constant C and tapered T sections of discharge pipe 60. The constant C and tapered T sections can have any suitable length. In one embodiment, the maximum length of the constant C section of the discharge pipe 60 is determined by the distance that the solid material can travel within the discharge pipe 60 until the expansion area 65 is filled with material 12. In one embodiment, the constant C section of the discharge pipe 60 is converted to a tapered T section of a discharge pipe 60 is a distance less than the distance that the solid material 12 can travel within the discharge pipe 60 until the expansion area 65 is filled with material 12. The length of tapered discharge pipe 60 can vary depending upon the size of the discharge pipe 60 and the properties of the material 12. In one embodiment, the length of the tapered discharge pipe 60 is sufficient to re-introduce an expansion area 65 above the material 12 within the discharge pipe 60. In one embodiment, the tapered T and/or constant C section of the discharge pipe 60 have a length of at least 1 linear foot, or at least about 3 linear feet, or at least about 5 linear feet and less than about 10 linear feet or less than about 7 linear feet.

In one embodiment, the discharge pipe 60 can include a low friction coating on the interior surfaces 63, 64 of the sidewalls 67, 68 to reduce friction between the sidewalls 67, 68 and the high solids material. Low friction surface coatings generally have a coefficient of friction of less than about 0.30, or less than about 0.20, less than about 0.10, or less than about 0.05, or between about 0.05 to 0.20, depending on the load, sliding speed, and particular coating used. Low friction surface coatings are known and include, but are not limited to materials such as glass or polymeric coatings such as Polytetrafluoroethylene (PTFE, trade name Teflon®); molybdenum disulfide (MoS₂); tungsten disulfide (WS₂); and graphite.

In another embodiment (shown in FIG. 20), the discharge pipe 60 can include one or more longitudinal ribs 71 extending along one or more interior surfaces 63, 64, of the sidewalls 67, 68 or cover 69 to reduce the surface area of the discharge pipe 60 in contact with the compressed block of material 12. In FIG. 20, the longitudinal ribs are shown as indentations 71 along the interior sidewall that create an open space 72 between the block of compressed material 12 and the interior surface of the discharge pipe 60. In other embodiments, the ribs can include ridges or projections extending from one or more interior surfaces of the discharge pipe 60.

In Use

In use, a loosely packed high solids material is transferred to collection hopper 20 through the opening 21 thereof. If desired, the high solids material can be shredded prior to placement in hopper. The size of the shredded material can vary, for example, depending upon the size of the pump or properties of the material. In one embodiment, the material is shredded into pieces having a maximum dimension that is less than about ½ the size of the chamber 32, less than about ⅓ the size of the chamber 32, less than about ¼ the size of the chamber, or less than about ⅛ the size of the chamber. For example for a 3 inch chamber, the material can be shredded in to pieces having a maximum dimension of 1 inch, for example, a maximum dimension of 1 inch×0.2 inches, or a maximum dimension of 0.5 inches×0.2 inches. For example for a 30 inch chamber, the material can be shredded in to pieces having a maximum dimension of 10 inches, for example, a maximum dimension of 10 inches×2 inches or a maximum dimension of 5 inches×2 inches.

With the ram 50 in the rearward or refracted position, the high solids material is fed into the inlet opening 33 of the hopper 20 and into the chamber 32. Ram 50 reciprocates in chamber 32 as previously described. As the ram 50 advances in the chamber 32 it moves the high solids material collected therein forward toward the discharge pipe 60. Upon retraction of the ram 50, additional high solids material can be transferred into the chamber 32.

When the high solids material is advanced by the ram 50 in the chamber 32, it may be compacted into a shape defined by the interior surface of the chamber 32. In one embodiment, the interior surface is a triangle defined by the sidewalls 37, 39 and cover 39 of the chamber 32. In this embodiment, when the high solids material is compressed by the ram 50, the material forms a triangular block. When the interior surface of the chamber defines some other shape, such as a trapezoid or square, the material will become compressed into a correspondingly shaped block of material.

When the material is released from the discharge opening 40 of the chamber 32, the high solids material does not immediately return to its original loosely packed state. Instead, some materials remain substantially in the shape of the compressed block. When non-circular blocks of material are released into a conventional circular discharge pipe, for example, the exterior surfaces of the blocks of material do not align with the interior surface of the circular discharge pipe. As such, the blocks can rotate (side-to-side) or tip (forwards and backward). The disorderly aggregation of blocks can result in the formation of a jam that can form a blockage in the discharge pipe. As additional blocks of material are introduced into the discharge pipe from the chamber, the blockage increases in size. Eventually, the pressure exerted by the barrier on the interior surface of the discharge pipe results in frictional forces that exceed the pumping pressure of the apparatus 10 and the solids material can no longer be advanced along the length of the discharge pipe. To remove the barrier, the equipment must be shut down to remove jam, costing valuable time and money.

In contrast, when blocks of material are released from the chamber 32 into a correspondingly shaped discharge pipe 60, the exterior surfaces of the block align with the interior surfaces of the discharge pipe 60, reducing the likelihood that the blocks will rotate or tip and cause a blockage in the discharge pipe.

In one embodiment, the discharge pipe 60 is tapered such that an inlet 61 of the pipe 60 has a smaller dimension than an outlet 62 of the pipe. When the blocks of high solids material are fed into a tapered discharge pipe, the blocks of material gradually expand as they advance from the proximal end 70 towards the distal end 75 of the discharge pipe 60. At distal end 75 of the discharge pipe 60, the material returns to a loosely packed state (i.e., the material is no longer a block).

At distal end 75 of the discharge pipe 60, the high solids material is subject to very little pressure (as compared to the proximal end 70 of the discharge pipe 60). Due to the compressibility of the high solids material, the exit of the material from the discharge pipe 60 outlet 62 can be stopped using minimal force. If a blockage occurs in the discharge pipe 60 when the outlet 76 is obstructed, the blockage will generally occur near the proximal end 70 of the discharge pipe 60. Furthermore, once the obstruction is removed from the distal end 75 of the discharge pipe 60, the blockage near the proximate end 70 will tend to dissipate on its own.

Working Example

Office paper was shredded into rectangles having an approximate dimension of 1 inch×0.2 inches to form a high-solids material. The loosely packed shredded paper was introduced into the chamber of a 3 inch chamber (i.e., a right-triangle shaped chamber in which the right angle formed the base of the chamber and which had a 3 inch hypotenuse). The 3 inch pump was connected to a 3 inch (diameter) round discharge pipe.

The total distance that the material was able to be pumped was only about 24 inches from the outlet of the chamber before a jam occurred, when pumped at a pressure of 350 PSI.

A tapered right-triangle 48 inch long discharge pipe was then attached to the pump. The right angle of the discharge pipe was oriented at the base or apex 66 of the discharge pipe and the top or hypotenuse of the triangle was measured 3⅛ inches at the inlet 61 and 3½ inches at the outlet 62 (see FIGS. 11 and 12). The inlet 61 of the tapered discharge pipe 60 was slightly larger than the discharge opening 40 of the chamber 32 to allow for a first decompression of material.

A 5 foot a section of constant discharge pipe having a size of 3½ inches at the inlet 61 and 3½ inches at the outlet 62 (see FIGS. 13 and 14) was attached to the outlet 61 of the tapered pipe. Thus the total length of the discharge pipe was 9 feet (see FIGS. 9 and 10).

Using this configuration, the material was able to be pumped at a pressure of 350 PSI along the entire 9 linear foot distance with out any blockage or plugging. The pressure in the chamber was then reduced to 125 PSI. The material was still able to be pumped along the entire 9 linear foot distance without any blockage or plugging. Thus, by using a triangular shaped discharge pipe, the chamber pressure could be decreased by approx. ⅓ and the pumping distance could still be increased by more than 4 times (as compared to a circular discharge pipe).

Two additional sections were then added to the discharge pipe. The third section was 5 feet long and 3½ inches at the inlet and 4 inches at the outlet. The forth section was 5 feet long and 4 inches at the inlet and 5 inches at the outlet, providing a discharge pipe having a length of 19 feet. When pumped at a pressure of 125 PSI, the material was able to be pumped the entire 19 feet without blockage. Thus, the material was pumped approximately 10 times the original distance of 2 feet at a ⅓ the original pressure.

It should be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

It should also be noted that, as used in this specification and the appended claims, the phrase “configured” describes a system, apparatus, or other structure that is constructed or configured to perform a particular task or adopt a particular configuration. The phrase “configured” can be used interchangeably with other similar phrases such as “arranged”, “arranged and configured”, “constructed and arranged”, “constructed”, “manufactured and arranged”, and the like.

All publications and patent applications in this specification are indicative of the level of ordinary skill in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated by reference.

This application is intended to cover adaptations or variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not restrictive. It should be readily apparent that any one or more of the design features described herein may be used in any combination with any particular configuration. With use of a molding process, such design features can be incorporated without substantial additional manufacturing costs. That the number of combinations are too numerous to describe, and the present invention is not limited by or to any particular illustrative combination described herein. The scope of the present subject matter should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. 

1. A material moving apparatus comprising: (a) a chamber having a cross-sectional shape and a discharge opening; (b) a ram mounted in the chamber configured to move material out of the discharge opening of the chamber; and (c) a discharge pipe connected to the discharge opening of the chamber and having an inlet and an outlet and a cross-sectional shape corresponding to the chamber cross-sectional shape.
 2. The material moving apparatus of claim 1, wherein the discharge pipe has a constant size such that the discharge pipe outlet has a size that is substantially the same as the discharge pipe inlet size.
 3. The material moving apparatus of claim 1, wherein the discharge pipe is tapered such that the discharge pipe outlet has a size that is greater than the discharge pipe inlet size.
 4. The material moving apparatus of claim 1, wherein the discharge pipe includes one or more sections.
 5. The material moving apparatus of claim 4, wherein the discharge pipe includes a substantially constant section in which the inlet size and the outlet size are substantially the same and a tapered section in which the outlet size is greater than the inlet size.
 6. The material moving apparatus of claim 4, wherein the sections of discharge pipe have a stepped configuration in which the inlet size of a distal discharge pipe section is greater than the outlet size of an adjacent proximal discharge pipe section.
 7. The material moving apparatus of claim 4, wherein the sections of discharge pipe include sections selected from the group consisting of constant, tapered and stepped sections.
 8. The material moving apparatus of claim 6, wherein the discharge pipe includes alternating constant and tapered sections.
 9. The material moving apparatus of claim 1, wherein the chamber comprises first and second downwardly converging side walls defining a longitudinal chamber with a discharge opening having a downwardly converging cross-sectional shape and the discharge pipe has a corresponding downwardly converging cross-sectional shape.
 10. The material moving apparatus of claim 9, wherein the downwardly converging sidewalls converge at a point and the chamber has a triangular cross-sectional shape and the discharge pipe has a corresponding triangular cross-sectional shape.
 11. The material moving apparatus of claim 1, wherein the inlet of the discharge pipe has a cross-sectional shape that is similar to the cross-sectional shape of the discharge opening of the chamber.
 12. The material moving apparatus of claim 1, wherein the inlet of the discharge pipe has a size that is the same as the discharge opening of the chamber.
 13. The material moving apparatus of claim 1, wherein the inlet of the discharge pipe has a size that is greater than the size of the discharge opening.
 14. The material moving apparatus of claim 1, further comprising a low friction coating on one or more interior surfaces of the discharge pipe.
 15. The material moving apparatus of claim 1, further comprising one or more longitudinal ribs along one or more interior surfaces of the discharge pipe.
 16. A material moving apparatus comprising: (a) a chamber having a triangular cross-sectional shape and discharge opening having a triangular cross-sectional shape; (b) a ram mounted in the chamber configured to move material out of the discharge opening of the chamber; and (c) a discharge pipe connected to the discharge opening of the chamber and having an inlet and an outlet and a triangular cross-sectional shape corresponding to the triangular chamber cross-sectional shape.
 17. A method for pumping a high-solids material comprising: (a) placing the high-solids material in a pumping chamber having a cross-sectional shape and discharge opening; (b) pumping the high-solids material out of the discharge opening of the chamber into a discharge pipe connected to the discharge opening of the chamber, wherein the discharge pipe has an inlet and an outlet and a cross-sectional shape corresponding to the cross-sectional shape of the chamber.
 18. The method of claim 17, wherein the high-solids material comprises at least 10% solids by weight.
 19. The method of claim 17, wherein the high-solids material is compressible.
 20. The method of claim 17, wherein the high-solids material is selected from the group consisting of: bio-solids, including, saw dust, yard trimmings, compost, wood chips, straw, grass, corn cobs, and corn stover; garbage or waste material, including, bottles, cans, clothing, disposables, food packaging, and food scraps; paper materials, including, newspapers, magazines, cardboard, office paper, and paper bags; plastic materials, including milk jugs and other storage containers; and mixtures and combinations thereof. 